O,s-dialkyl-o-(4-phenylazophenyl)-thiophosphates and pesticidal compositions thereof

ABSTRACT

Organophosphorus acid esters of the formula ##STR1## wherein R 1  represents propyl or butyl; R 2  represents methyl or ethyl; each of R 3  and R 4  represents hydrogen, halogen, or alkyl having 1 to 5 carbon atoms; n is a number from 1 to 4; and m is a number from 1 to 5. These compounds are useful for the control of insects, acarids and nematodes.

Cross-Reference to Related Application

This is a continuation-in-part of application Ser. No. 377,855=filedJuly 9, 1973 now abandoned

The present invention relates to new organophosphorus acid esters, topesticidal compositions containing them, and to their use forcontrolling pests, particularly insects, acarids and nematodes.

The compounds have the formula ##STR2## wherein R₁ represents propyl orbutyl; R₂ represents methyl or ethyl; each of R₃ and R₄ representshydrogen, halogen, or alkyl having from 1 to 5 carbon atoms; n is anumber from 1 to 4; and m is a number from 1 to 5.

By halogen is meant fluorine, chlorine, bromine, or iodine, butespecially chlorine or bromine.

THe alkyl groups R₃ and R₄ can be straight-chain or branched. Examplesof such groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec.butyl, tert.butyl, n-pentyl and isomers thereof. The alkylgroup R₁ can be any C₃ or C₄ alkyl, straight-chain or branched.

Of particular interest are compounds of formula I in which R₁ is propylor butyl; R₂ is methyl or ethyl; each of R₃ and R₄ is hydrogen, chlorineor methyl; n is 1; and m is 1 or 2.

Preferred are compounds of formula I in which R₁ is n-propyl, isopropylor isobutyl.

According to a more preferred embodiment of this invention, thecompounds have the formula ##STR3## in which R₁ is n-propyl or isobutyl;R₂ is methyl or ethyl; and R₄ is hydrogen, chlorine or methyl in the 2-or 4-position. Especially preferred are compounds of formula II in whichR₁ is n-propyl, R₂ is ethyl and R₄ is in the 4-position.

The compound of formula I are manufactured by the following knownmethods; ##STR4##

In the formulae III to IX, R₁, R₂, R₃, R₄, n and m have the meaningsgiven for the formula I. Hal represents a halogen atom, in particularchlorine. Me represents an alkali metal, especially sodium or potassium,an ammonium or alkylammonium group.

Suitable acid acceptors are: tertiary amines, e.g. trialkylamine,pyridine, dialkyl anilines; inorganic bases, e.g. hydrides, hydroxides,carbonates and bicarbonates or alkali metals and alkaline earth metals.It is sometimes necessary to use catalysts in the reactions, for examplecopper or copper chloride. Processes 1a, 1b, and 2 are carried out at areaction temperature between -2° C and 130° C, at normal pressure, andin solvents or diluents.

Examples of suitable solvents or diluents are: ether and etherealcompounds, e.g. diethyl ether, dipropyl ether, dioxan, tetrahydrofuran;amides, e.g. N,N-dialkylated carboxylic acid amides; aliphatic,aromatic, and halogenated hydrocarbons, in particular benzene, toluene,xylene, chloroform, chlorobenzene; nitriles, e.g. acetonitrile; dimethylsulphoxide; ketones, e.g. acetone, methyl ethyl ketone; and water.

The starting materials of the formulae III, IV, V, VI, VII and IX can bemanufactured in analogous manner to known methods.

The compounds of formula I have a board biocidal activity spectrum andcan therefore be used for combating various plant and animal pests. Inparticular, they are suitable for combatting insects, acarids, andnematodes. Insects combatted include the families: Acrididae, Blattidae,Gryllidae, Gryllotalpidae, Tettigoniidae, Cimicidae, Phyrrhocoridae,Reduviidae, Aphididae, Delphacidae, Diaspididae, Pseudoccidae,Chrysomolidae, Coccinellidae, Bruchidae, Scarabaeidae, Dermestidae,Tenebrionidae, Curcurionidae, Tineidae, Noctuidae, Lymantriidae,Pyralidae, Galleriidae, Culicidae, Tipulidae, Stomoxydae, Muscidae,Calliphoridae, Trypetidae and Pulicidae. Acarids combatted include thefamilies: Ixodidae, Argasidae, Tetranychidae and Dermanyssidae.

By addition of other insecticides and/or acaricides it is possible toimprove substantially the insecticidal or acaricidal action and to adaptit to given circumstances.

In addition, the compounds of formula I also display activity againstrepresentatives of the division Thallophyta. Thus, a number of thesecompounds display bactericidal action. But they are active particularlyagainst phytophatogenic fungi which belong to the following classes:Oomycetes, Zygomycetes, Ascomycetes, Basidiomycetes and Denteromycetes.The compounds of formula I also evidence a fungitoxic action againstfungi which attack the plants from the soil. Further, these newcompounds are also suitable for treating seeds, fruit, tubers, etc., toprotect them from fungus infections. The compounds of formula I are alsosuitable for combatting plant pathogenic nematodes.

In U.S. Pat. No. 2,947,663, there are disclosed 0,0-dialkyl-0-l-(4-phenylazophenyl)-phosphate and -thiophosphates of the formula##STR5## in which R₁ and R₂ represent methyl or ethyl; R₄ representshydrogen, halogen, nitro, methyl, methoxy or ethoxy; and X representsoxygen or sulphur. The new compounds of formula I differ from the knowncompounds of formula X in that they are asymmetric "mixed" esters.Rather than having two identical alkoxy groups; the compounds of formulaI have one alkoxy group and one alkylthio group. Furthermore, in thesealkoxy and alkylthio groups, the alkyl moieties are different; inparticular, the alkyl moiety of the alkoxy group is methyl or ethyl andthe alkyl moiety of the akylthio group is a propyl or butyl radical. Thecombined effect of these two differences results in compounds havingsuperior insecticidal effectiveness and, in many cases, lower mammaliantoxicity than the previously known analogues.

The compounds of formula I may be used as pure active substance ortogether with suitable carriers and/or additives. Suitable carriers andadditives can be solid or liquid and correspond to the substancesconventionally used in formulation technique such, for example, assolvents, dispersants, wetting agents, adhesives, thickeners, bindersand/or fertilizers.

For application, the compounds of formula I may be processed to dusts,emulsion concentrates, granules, dispersions, sprays, solutions, orsuspensions, in the conventional formulation which is commonly employedin application technology, Mention may also be made of cattle dips andspray races, in which aqueous preparations are used.

The compositions according to the invention are manufactured in knownmanner by intimately mixing and/or grinding active substances of formulaI with the suitable carriers, optionally with the addition ofdispersants or solvents which are inert towards the active substances.The active substances may take, and be used in, the following forms:

Solid forms;

Dusts, tracking agents, granules, coated granules, impregnated granulesand homogeneous granules.

Liquid forms:

a. active substances which are dispersible in water; wettable powders,pastes, emulsions,

b. solutions.

To manufacture solid forms (dusts, tracking agents), the activesubstances are mixed with solid carriers. Suitable carriers are, forexample: kaolin, talcum, bolus, loess, chalk, limestone, groundlimestone, attaclay, dilomite, diatomaceous earth, precipitated silica,alkaline earth silicates, sodium and potassium aluminium silicates(feldspar and mica), calcium and magnesium sulphates, magnesium oxide,ground synthetic materials, fertilizers, for example ammonium sulphate,ammonium phosphate, ammonium nitrate, urea, ground vegetable products,such as corn meal, bark dust, sawdust, nutshell meal, cellulose powder,residues of plant extractions, activated charcoal, etc. These substancescan either be used singly or in admixture with one another.

Granules can be very easily manufactured by dissolving an activesubstance of formula I in an organic solvent and applying the resultingsolution to a granulated material, for example attapulgite, SiO₂,granicalcium, bentonite, etc., and then evaporating the solvent.

Polymer granules can also be manufactured by mixing the activesubstances of formula I with polymerisable compounds (urea/formaldehyde;dicyandiamide/formaldehyde; melamine/formaldehyde or others), whereupona mild polymerization is carried out that does not affect the activesubstances and in the process of which the granulation is carried outduring the gel formation. It is more advantageous to impregnatefinished, porous polymer granules (urea/formaldehyde, polyacrylonitrile,polyester or others) which have a specific surface area and a favorablepredeterminable adsorption/desorption ratio, with the active substances,for example in the form of their solutions (in a low boiling solvent)and to remove the solvent. Polymer granules of this kind in the form amicrogranules having a bulk density of 300 g/liter to 600 g/liter canalso be manufactured with the aid of atomizers. The dusting can becarried out from aircraft over extensive areas of cultures of usefulplants.

It is also possible to obtain granules by compacting the carrier withthe active substance and carriers and subsequently comminuting theproduct.

To these mixtures can also be added additives which stabilize the activesubstance and/or non-ionic, anionic and cationic surface activesubstances, which, for example, improve the adhesion of the activeingredients on plants or parts of plants (adhesives and agglutinants)and/or ensure a better wettability (wettng agents) and dispersibility(dispersing agents). Examples of suitable adhesives are the following:olein/chalk mixture, cellulose derivatives (methyl cellulose,carboxymethyl cellulose), hydroxyethyl glycol ethers of moroalkyl anddialkyl phenols having 5 to 15 ethylene oxide radicals per molecule and8 to 9 carbon in the alkyl radical, lignin sulphonic acids, their alkalimetal and alkaline earth metal salts, polyethylene glycol ethers(Carbowax), fatty alcohol polyethylene glycol ethers having 5 to 20ethylene oxide radicals per molecule and 8 to 10 carbon atoms in thefatty alcohol moiety, condensation products of ethylene oxide/propyleneoxide, polyvinyl pyrrolidones, polyvinyl alcohols, condensation productsof urea and formaldehyde, and also latex products.

The water-dispersible concentrates of the active substance, i.e.,wettable powders, pastes and emulsifiable concentrates, are agents whichcan be diluted with water to any concentration desired. They consist ofactive substance, carrier, optionally additives which stabilize theactive subsance, surface-active substance and anti-foam agents and,optionally, solvents.

Wettable powders and pastes are obtained by mixing and grinding theactive substances with dispersing agents and pulversulent carriers insuitable apparatus until homogeneity is attained. Suitable carriers are,for example, those mentioned for the solid forms of application. In somecases, it is advantageous to use mixtures of different carriers. Asdispersing agents, there can be used, for example, condensation productsof sulphonated naphthalene and sulphonated naphthalene derivatives withformaldehyde, condensation products of naphthalene or naphthalenesulphonic acids with phenol and formaldehyde, as well as alkali,ammonium and alkaline earth metal salts of lignin sulphonic acid, inaddition, alkylaryl sulphonates, alkali and alkaline earth metal saltsof dibutyl naphthalene sulphonic acid, fatty alcohol sulphates such assalts of sulphated hexadecanols, heptadecanols, octadecanols, and saltsof sulphated fatty alcohol glycol ethers, the sodium salt of oleoylethionate, the sodium salts of oleoyl methyl tauride, ditertiaryacetylene glycols, dialkyl dilauryl ammonium chloride and fatty acidalkali and alkaline earth metal salts.

Suitable anti-foam agents are silicones.

The active substances are mixed, ground, sieved and strained with theadditives cited hereinabove, in such a manner that, the size of thesolid particles does not exceed 0.02 to 0.04μ in wettable powders, and0.03μ in pastes. To produce emulsifiable concentrates and pastes,dispersing agents such as those cited above, organic solvents, and waterare used. Examples of suitable solvents are: alcohols, benzene, xylene,toluene, dimethyl sulphoxide, and mineral oil fractions which boilbetween 120° and 350° C. The solvents must be practically odorless, notphytotoxic, and inert to the active substances.

Furthermore, the agents according to the invention can be applied in theform of solutions. For this purpose, the active substances, or severalactive substances of the general formula I, are dissolved in suitableorganic solvents, mixtures of solvents or in water. Aliphatic andaromatic hydrocarbons, chlorinated derivatives thereof, alkylnaphthalenes and mineral oils, singly or in admixture with each other,can be used as organic solvents.

The content of active substance in the above described agents is between0.1% to 95%, in which connection it should be mentioned that, in thecase of application from aircraft or some other suitable means ofapplication, it is possible to use concentrations of up to 99.5% or evenpure active substance.

The active substances of formula I can, for example, be formulated asfollows:

Dusts

The following substances are used to manufacture (a) a 5% and (b) a 2%dust;

(a)

5 parts of active substance

95 parts of talcum

(b)

2 parts of active substance

1 paat of highly disperse silicic acid

97 parts of talcum.

The active substances are mixed with the carriers and ground.

Granules

The following substances are used to produce 5% granules:

5 parts of active substance,

0.25 parts of epichlorohydrin,

0.25 parts of cetyl polyglycol ether,

3.50 parts of polyethylene glycol,

91 parts of kaolin (particle size 0.3 - 0.8 mm).

The active substance is mixed with epichlorohydrin and dissolved with 6parts of acetone; and polyethylene glycol and cetyl polyglycol ether arethen added. The thus obtained solution is sprayed on kaolin, and theacetoe subsequently evaporated in vacuo.

Wettable powder

The following constituents are used for the preparation of (a) a 40%,(b) and (c) a 25%, and (d) a 10% wettable powder:

(a)

40 parts of active substance,

5 parts of sodium lignin sulphonate,

1 part of sodium dibutyl-naphthalene sulphonate,

54 parts of silicic acid.

(b)

25 parts of active substance,

4.5 parts of calcium lignin sulphonate,

1.9 parts of Champagne chalk/hydroxyethyl cellulose mixture (1:1),

1.5 parts of sodium dibutyl naphthalene sulphonate,

19.5 parts of silicic acid,

19.5 parts of Champagne chalk,

28.1 parts of kaolin.

(c)

25 parts of active substance,

2.5 parts of isooctylphenoxy-polyoxyethylene-ethanol,

1.7 parts of Champagne chalk/hydroxyethyl cellulose mixture (1:1),

8.3 parts of sodium aluminium silicate,

16.5 parts of kieselguhr,

46 parts of kaolin,

(d)

10 parts of active substance,

3 parts of a mixture of the sodium salts of saturated fatty alcoholsulphates,

5 parts of naphthalenesulphonic acid/formaldehyde condensate

82 parts of kaolin.

The active substances are intimately mixed, in suitable mixers, with theadditives, the mixture being then ground in the appropriate mills androllers. Wettable powders are obtained which can be diluted with waterto give suspensions of any desired concentration.

EMULSIFIABLE CONCENTRATES

The following substances are used to produce (a) a 10% and (b) a 25%emulsifiable concentrate:

10 parts of active substance,

3.4 parts of epoxidized vegetable oil,

13.4 parts of a combination emulsifier consisting of fatty alcoholpolyglycol ether and alkylarylsulphonate calcium salt,

40 parts of dimethylformamide,

43.2 parts of xylene.

(b)

25 parts of active substance,

2.5 parts of epoxidized vegetable oil,

10 parts of an alkylarylsulphonate/fatty alcohol-polyglycol ethermixture,

5 parts of dimethylformamide,

57.5 parts of xylene.

From these concentrates it is possible to produce, by dilution withwater, emulsions of any desired concentration.

Spray

The following constituents are used to prepare a 5% spray:

5 parts of active substance,

1 part of epichlorohydrin,

94 parts of benzine (boiling limits 160° - 190° C).

The invention will be better understood by reference to the followingexamples which are included here for exemplification only and not aslimitations.

EXAMPLE 1

At room temperature 10.1 g of O-ethyl-S-n-propyl-thio-phosphoricchloride in 25 ml of absolute ether are added dropwise to a solution of11.6 g of 4-hydroxy-4'-chloro-azobenzene and 5.1 g of triethylamine in150 ml of absolute ether. The salt precipitate is filtered off and themixture is treated with 200 ml of ice water with stirring. The organicphase is isolated, washed once with water and shaken twice with ice-cold5% sodium hydroxide solution and then washed neutral with water. Theethereal phase is then treated with activated charcoal, filtered, dried,and the solvent is evaporated. The residue is dried for 3 hours at 70° Cand 0.1 Torr to give the compound of the formula ##STR6## withrefractive index of n_(D) ²⁰° = 1.6185.

The following compounds are also manufactured in analogous manner:

    __________________________________________________________________________    No.                                                                              Structure                      Refractive Index                            __________________________________________________________________________     2                                                                                ##STR7##                       n.sub.D.sup.20 = 1.6142                     3                                                                                ##STR8##                       n.sub.D.sup.20 = 1.6251                     4                                                                                ##STR9##                       n.sub.D.sup.20 = 1.6300                     5                                                                                ##STR10##                       n.sub.D.sup.20 = 1.6132                    6                                                                                ##STR11##                      n.sub.D.sup.20 = 1.6082                     7                                                                                ##STR12##                      n.sub.D.sup.20 = 1.6078                     8                                                                                ##STR13##                      n.sub.D.sup.20 = 1.6018                    __________________________________________________________________________

example 2 action against ticks

A. Rhipicephalus bursa

Five adult ticks and 50 tick larvae were counted into a glass tube andimmersed for 1 to 2 minutes in 2 ml of an aqueous emulsion from anemulsion series each containing 100, 10, 1 and 0.1 ppm of testsubstance. The tube was then sealed with a standardized cotton wool plugand placed on its head, so that the active substance emulsion could beadsorbed by the cotton wool.

In the case of the adults, evaluation took place after 2 weeks, and inthat of the larvae, after 2 days. Each test was repeated twice.

B. Boophilus microplus (larvae)

Tests were carried out in each case with 20 OP-sensitive larvae using ananalogous dilution series as in the case of test A. (The OP-sensitivityrefers to Diazinon).

The compounds according to Example 1 were active in these tests againstadults and larvae of Rhipicephalus bursa sensitive and OP-resistantlarvae of Boophilus microplus.

EXAMPLE 3 Action against Chilo suppresalis

Six rice plants at a time of the variety Caloro' were transplanted intoplastic pots (diameter at the top - 17 cm) and reared to a height ofabout 60 cm. Infestation with Chilo suppressalis larvae (L₁ : 3-4 mmlong) took place 2-days after the active substance had been applied ingranule form to the paddy water (rate of application: 8 kg of activesubstance per hectare). Evaluation of the insecticidal action took place10 days after application of the granules.

The compounds according to Example 1 were active in the above testsagainst Chilo suppressalis.

EXAMPLE 4 Action against soil insects

Sterilized compost earth was homogenously mixed with a wettable powdercontaining 25% of active substance so that there resulted a rate ofapplication of 5 kg of active substance per hectare.

Young zucchetti plants (Cucumis pepo) were put into plastic pots withthe treated soil (3 plants per pot; diameter of pot = 7 cm). Each potwas infected immediately afterwards with 5 Aulacophora femoralis andPachmoda or Chortophila larvae. The control was carried out 4, 8, 16 and32 days after depositing the larvae.

At 80-100% kill after the first control, a fresh infestation with 5larvae each was carried out in the same soil sample with 3 new zucchettiplants. If the activity was less than 80%, the remaining larvae remainedin the soil sample until the control immediately following. If an activesubstance at a rate of application of 8 kg/ha still effected a 100%kill, a further control with 4 and 2 kg of active substance per hectarewas carried out.

EXAMPLE 5 Acaricidal Action

Phaseoulus vulgaris (dwarf beans) had an infested piece of leaf from amass culture of Tetranychus urticae placed on them 12 hours before thetest for the acaricidal action. The mobile stages which have migratedare sprayed with the emulsified test preparations from a chromatographyatomizer so thatthe spray broth does not run off. The number of livingand dead larvae, adults and eggs are evaluated after 2 to 7 days under astereoscopic microscope and the result expressed in percentages. Duringthe interim, the treated plants are kept in greenhouse compartments at25° C.

The compounds according to Example 1 were active in the above testagainst eggs, larvae and adults of Tetranychus urticae.

EXAMPLE 6 Action against Soil Nematodes

To test the action against soil nematodes, the active substance isapplied to and intimately mixed with soil infected with root gallnematodes (Meloidgyne arenaria). Immediately afterwards, tomato cuttingsare planted in the prepared soil in a series of tests and after awaiting time of 8 days, tomato seeds are sown in another test series.

In order to assess the nematocidal action, the galls present on theroots are counted 28 days after planting and sowing respectively. Inthis test the compounds according to Example 1 display good actionagainst Meloidgyne arenaria.

EXAMPLE 7 Comparative Insectidical Tests

Compounds within the scope of formula II of this invention

O-ethyl-S-n-propyl-O-[4-(4'-chlorophenylazo)-phenyl]-thiophosphate --compound No. 1

O-ethyl-S-n-propyl-O-(4-phenylazophenyl)-thiophosphate -- compound No. 2

O-ethyl-S-n-propyl-O-[4-(4'-methylphenylazo)-phenyl]-thiophosphate --compound No. 5

were compared with compounds of U.S. Pat. No. 2,947,663

O,o-diethyl-O-(4-phenylazophenyl)-phosphate -- compound A

O,o-diethyl-O-[4-(4'-chlorophenylazo)-phenyl]-phosphate -- compound B

O,o-diethyl-O-[4-(4'-methylphenylazo)-phenyl]-phosphate -- compound C

O,o-diethyl-O-[4-(4'-chlorophenylazo)-phenyl]-thiophosphate -- compoundD

O,o-diethyl-O-[4-(4'-methylphenylazo)-phenyl]-thiophosphate -- compoundE

in their action against Spodoptera littoralis.

Potato plants in the 4 to 5 leaf stage were treated by immersion in an0.1% aqueous emulsion of the compound under test, the emulsion havingbeen prepared from a 25% wettable powder. After drying, each plant wassettled with 5 larvae of the species Spodoptera littoralis at the L-3instar. Plastic cylinders covered with wire netting at the top were thenplaced over each of the plants to prevent the larvae from straying. Theplants were examined after three days and the percentage of dead larvaeestimated in each case. The test was conducted at 24° C and 60% relativehumidity.

                  TEST RESULTS                                                    ______________________________________                                        Test                                                                          Compound 1      B      D    2    A    5    C    E                             ______________________________________                                        % mortality                                                                   after                                                                         3 days   100    0      0    100  0    100  0    0                             ______________________________________                                    

Compound numbers 1, 2 and 5, according to this invention, showed a goodactivity against Spodoptera littoralis larvae in the above test.Compounds A, B and C, according to U.S. Pat. No. 2,947,663, showed zeroactivity.

We claim:
 1. A compound of the formula ##STR14## wherein R₁ representspropyl or butyl; R₂ represents methyl or ethyl; each of R₃ and R₄represents hydrogen, halogen or alkyl having from 1 to 5 carbon atoms; nis a number from 1 to 4; and m is a number from 1 to
 5. 2. A compoundaccording to claim 1 in which each of R₃ and R₄ represents hydrogen,chlorine or methyl; n is 1; and m is 1 or
 2. 3. A compound according toclaim 2 in which R₁ is n-propyl or isobutyl; R₃ is hydrogen; R₄ is inthe 2- or 4-position; and m is
 1. 4. The compound according to claim 3which isO-ethyl-S-n-propyl-O-[4-(4'-chlorophenylazo)-phenyl]-thiophosphate. 5.The compound according to claim 3 which isO-ethyl-S-n-propyl-O-(4-phenylazophenyl)-thiophosphate.
 6. The compoundaccording to claim 2 which isO-ethyl-S-n-propyl-O-[2-chloro-4-(4'-chlorophenylazo)-phenyl]-thiophosphate.7. The compound according to claim 2 which isO-ethyl-S-n-propyl-O-[4-(3',4'-dichlorophenylazo)-phenyl]-thiophosphate.8. The compound according to claim 3 which isO-ethyl-S-n-propyl-O-[4-(4'-methylphenylazo)-phenyl]-thiophosphate. 9.The compound according to claim 3 which isO-ethyl-S-isobutyl-O-(4-phenylazophenyl)-thiophosphate.
 10. A pesticidalcomposition comprising (1) a pesticidally effective amount of a compoundaccording to claim 1 and (2) a carrier.
 11. A composition according toclaim 10 in which, in the compound, each of R₃ and R₄ representshalogen, chlorine or methyl; n is 1; and m is 1 or
 2. 12. Thecomposition according to claim 11 in which the compound isO-ethyl-S-n-propyl-O-(4-phenylazophenyl)-thiophosphate.
 13. Thecomposition according to claim 11 in which the compound isO-ethyl-S-n-propyl-O-[2-chloro-4-(4'-chlorophenylazo)-phenyl]-thiophosphate.